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Hypocortisolism
- | ICD9 = | ICDO = | OMIM = | MedlinePlus = | eMedicineSubj = emerg | eMedicineTopic = 16 | MeshID = D000309 }} Adrenal insufficiency is a condition in which the adrenal glands, located above the kidneys, do not produce adequate amounts of steroid hormones (chemicals produced by the body that regulate organ function), primarily cortisol, but may also include impaired aldosterone production (a mineralcorticoid) which regulates sodium, potassium and water retention. Craving for salt or salty foods due to the urinary losses of sodium is common. Addison's disease, congenital adrenal hyperplasia, and Cushing's syndrome can manifest as adrenal insufficiency. If not treated, adrenal insufficiency may result in severe abdominal pains, diarrhea, vomiting, profound muscle weakness and fatigue, depression, extremely low blood pressure (hypotension), weight loss, kidney failure, changes in mood and personality, and shock (adrenal crisis). An adrenal crisis often occurs if the body is subjected to stress, such as an accident, injury, surgery, or severe infection; death may quickly follow. Adrenal insufficiency can also occur when the hypothalamus or the pituitary gland, both located at the base of the skull, does not make adequate amounts of the hormones that assist in regulating adrenal function. This is called secondary adrenal insufficiency and is caused by lack of production of ACTH in the pituitary or lack of CRH in the hypothalamus. Hypocortisolism, also known as Adrenal insufficiency. Cause from * Abrupt withdrawal of chronic exogenous glucocorticoid therapy ie: secondary adrenal insufficiency -> deficient in glucocorticoid and normal mineralocorticoid (excessive glucocorticoid -> inhibition of hypothalamas (CRH) and anterior pituitary (ACTH) -> atrophy -> no cortisol) * Primary adrenal insufficiency -> glucocordicoid, mineralocorticoid and adrenal androgen deficiency: destruction of the adrenal cortex (autoimmune disease or total destruction of adrenal gland from TB -> Addison’s disease – '''low mineralcorticoid can lead to hypovolemic shock: dehydration, low blood pressure and hyperkaleamia -> life threatening) **Hyperpgimentation of skin (only for primary adrenal insufficiency -> increase ACTH with a-MSH (by product of ACTH)) **Fasting hypoglycemia: low glucocorticoid -> reduce gloconeogenesis and reduce tissue insulin resistance) **Hypotension: low glucocorticoid -> reduce responsiveness to catecholamines and angiotensin II; in '''primary adrenal insufficiency low mineralcorticoid lead to contraction of intravascular vol **Hyperkalaemia, hyponatraemia metabolic acidosis (mineralcorticoid deficiency) **Weightloss **Weakness **Fatique (hyperkalemia) **Anorexia (cortisol stimulate appetite) **Poor tolerance to stress **Decreased axillary and pubic hair and loss of libido in women (loss of adrenal androgen) *aldosterone **control ***angiotensin (rennin-angiotensin system) ****low ECF volume (dehydration, diuretics, sodium depletion, upright posture) ****decrease in systemic bp (hemorrhage) ****low renal arterial pressure (sensed by stretch receptor in afferent arterioles of JG apparatus) ****increase renal sympathetic nerve discharge (B-adrenoreceptor) or catecholamines acting on juxtaglomerular cell ****low NaCl to the distal tubule (the filtered []) sensed by macula densa cells -> tells JGC to release rennin ***hyperkalemia ***ACTH less effective ***Hyponatremia *activate via binding to intracellular receptors (mineralocorticoid receptors/ type I glucocoticoid receptors) -> gene activation or repression; binding to cell surface receptors or binding sites to generate intracellular second msg **effects ***renal reabsorption of Na in distal tubule and collecting duct in exchange for K and H ***increase activity of epithelial sodium channels ***Na reabsorption ***K secretion ***H secretion **Hyperaldosteronism ***Primary hyperaldosteronism ****Conn’s syndrome ****Aldosterone secreting adrenal tumor (adenoma) or hyperplasia ***Secondary hyperaldosteronism ****Hyperreninism ****Renovascular sternosis *low plasma rennin activity (primary hyperaldosteronism) -> high aldosterone/ rennin ratio *sodium retention -> increase ECF vol and hypertension; Na normal <145mmol/L *increase K excretion -> hypokalemia *increase H excretion -> metabolic alkalosis *polyuria (resistance to ADH) ie: nephrogenic diabetes insipidus **Hypoaldosteronism ***Loss of Na -> low plasma volume, hypotension and circulatory collapse ***Hyperkalemia (due to decrease in minerocorticoid) ***Metabolic acidosis (low aldosterone -> reduce H secretion in exchange for Na reabsorption Types There are two major types of adrenal insufficiency. * Primary adrenal insufficiency is due to impairment of the adrenal glands. ** The most common subtype is called idiopathic or unknown cause of adrenal insufficiency. ** Some are due to an autoimmune disease called Addison's disease or autoimmune adrenalitis. ** Other cases are due to congenital adrenal hyperplasia or an adenoma (tumor) of the adrenal gland. * Secondary adrenal insufficiency is caused by impairment of the pituitary gland or hypothalamus. These can be due to a form of cancer: a pituitary microadenoma, or a hypothalamic tumor; Sheehan's syndrome, which is associated with impairment of only the pituitary gland; or a past head injury. * Tertiary adrenal insufficiency is due to hypothalamic disease and decrease in corticotropin releasing factor (CRF).http://www.endotext.org/adrenal/adrenal13/adrenal13.htm Causes Causes of acute adrenal insufficiency are mainly Waterhouse-Friderichsen syndrome, sudden withdrawal of long-term corticosteroid therapy and stress in patients with underlying chronic adrenal insufficiency. Table 20-7 in: 8th edition. The latter is termed critical illness–related corticosteroid insufficiency. For chronic adrenal insufficiency, the major contributors are autoimmune adrenalitis, tuberculosis, AIDS and metastatic disease. Minor causes of chronic adrenal insufficiency are systemic amyloidosis, fungal infections, hemochromatosis and sarcoidosis. Autoimmune adrenalitis may be part of Type 2 autoimmune polyglandular syndrome, which can include type 1 diabetes), hyperthyroidism, autoimmune thyroid disease (also known as autoimmune thyroiditis, Hashimoto's thyroiditis and Hashimoto's disease). Hypogonadism and pernicious anemia may also present with this syndrome. Adrenoleukodystrophy can also cause adrenal insufficiency. Adrenal Insufficiancy can also be caused is when a patient has a Craniopharyngioma which is a benign tumor that can damage the Pituitary gland causing the Adrenal Glands not to function. This would be an example of Secondary Adrenal Insufficiancy Syndrome. Symptoms :The person may show symptoms of hypoglycemia, dehydration, weight loss, and disorientation. He or she may experience weakness, tiredness, dizziness, low blood pressure that falls further when standing (orthostatic hypotension), muscle aches, nausea, vomiting, and diarrhea. These problems may develop gradually and insidiously. Addison's can present with tanning of the skin that may be patchy or even all over the body. Characteristic sites of tanning are skin creases (e.g. of the hands) and the inside of the cheek (buccal mucosa). Goitre and vitiligo may also be present. Diagnosis :If the person is in adrenal crisis, the ACTH stimulation test may be given. If not in crisis, cortisol, ACTH, aldosterone, renin, potassium and sodium are tested from a blood sample before the decision is made if the ACTH stimulation test needs to be performed. X-rays or CT of the adrenals may also be done. The best test for adrenal insufficiency of autoimmune origin, representing more than ninety percent of all cases in a Western population, is measurement of 21-hydroxylase autoantibodies. Treatment :*;Adrenal crisis ::*Intravenous fluids ::*Intravenous steroid (Solu-Cortef or Solumedrol), later hydrocortisone, prednisone or methylpredisolone tablets ::*Rest :*;Cortisol deficiency (primary and secondary) ::*Adrenal cortical extract (usually in the form of a supplement, non prescription in the United States) ::*Hydrocortisone (Cortef) (between 20 and 35 mg) ::*Prednisone (Deltasone) (7.5 mg) ::*Prednisolone (Delta-Cortef) (7.5 mg) ::*Methylprednisolone (Medrol) (6 mg) ::*Dexamethasone (Decadron) (0.25 mg, rarely up to 1 mg, but higher doses tend to cause side effects resembling Cushing's disease.) :*;Mineralcorticoid deficiency (low aldosterone) ::*Fludrocortisone (Florinef) (To balance sodium, potassium and increase water retention) Simple diagnostic chart Source of pathology 'CRH '''ACTH '''DHEA '''DHEA-S '''cortisol '''aldosterone '''renin '''Na '''K '''Causes'5 '''hypothalamus (tertiary)1 low low low low low3 low low low low tumor of the hypothalamus (adenoma), antibodies, environment (i.e. toxins), head injury pituitary (secondary) high2 low low low low3 low low low low tumor of the pituitary (adenoma), antibodies, environment, head injury, surgical removal'''6, Sheehan's syndrome '''adrenal glands (primary)7 high high high high low4 low high low high tumor of the adrenal (adenoma), stress, antibodies, environment, Addison's Disease, trauma, surgical removal (resection), miliary tuberculosis of the adrenal 1''' Automatically includes diagnosis of secondary (hypopituitarism) '''2 Only if CRH production in the hypothalamus is intact 3''' Value doubles or more in stimulation '''4 Value less than doubles in stimulation 5''' Most common, does not include all possible causes '''6 Usually because of very large tumor (macroadenoma) 7 Includes Addison's disease References / Riförènses / 參考資料 See also *Cushing's syndrome, overproduction of cortisol *Insulin tolerance test, another test used to identify sub-types of adrenal insufficiency *Hypoadrenia, the precursor to adrenal insufficiency, adrenal fatigue External links * Penn State University - Adrenal insufficiency * CAH - Congenital adrenal hyperplasia Category:Endocrinology Category:Adrenal gland disorders